Cytosolic thioredoxin peroxidase is essential for the antioxidant response of yeast with dysfunctional mitochondria.
Demasi, A. P. D., Pereira, G. A. G. and Soares Netto, L. E. FEBS Letters. 509(3):430-434 2001
The specific role of cytosolic thioredoxin peroxidase I (cTPx I), encoded by TSA1 (thiol-specific antioxidant), was investigated in the oxidative stress response of Saccharomyces cerevisiae. In most cases, deletion of TSA1 has showed only a slight effect on hydrogen peroxide sensitivity. However, when the functional state of the mitochondria was compromised, the necessity of TSA1 in cell protection against this oxidant was much more evident. All the procedures used to disrupt the mitochondrial respiratory chain promoted increases in the generation of H2O2 in cells, which could be related to their elevated sensitivity to oxidative stress. In fact, TSA1 is highly expressed when cells with respiratory deficiency are exposed to H2O2. In conclusion, our results indicate that cTPx I is a key component of the antioxidant defense in respiratory-deficient cells.
Apoio financeiro: FAPESP, CNPq